This invention relates to the wrapping of electrically conductive wires. The invention particularly relates to the stripping of electrical insulation from insulated wires prior to the uninsulated wire being wrapped on a wrapping post.
Frequently it is necessary to wrap an electrically conductive wire around a wrapping post. The wires, for example telephone wires, have an outer insulating sheath which often has to be stripped from the wire prior to the wire being wrapped in order to enable a good contact to be established between the wire and the wrapping post. A known wrapping tool comprises a wrapping head which in use is located coaxially with the wrapping post so that it can be rotated about the wrapping post. The wrapping head carries a stripping plate which is positioned so that the wire to be wrapped passes through a stripping slot in the plate immediately prior to being wrapped on the post. The size of the slot is such that the central electrically conductive core can pass therethrough but the outer insulating sheath is removed by the plate. The head is generally formed with a shaft which can be connected to a conventional pistol gun for rotating the head. The shaft on the wrapping tool can if necessary be connected to the gun via a holder which includes a wire cutter for cutting the wire to a pre-selected length prior to wrapping.
This known type of wrapping head operates on the principle that in order to obtain a reliable wire wrap a high tension usually has to be introduced into the wrap during terminating particularly when the insulation material is foamed polyethylene. The high tension can be tolerated when dealing with copper conductors but can cause problems of wire breakage due to excessive tension when aluminium conductors are used.
We have now found that it is possible to strip and wrap wires with a reduced tension using a wrapping head which includes a cutting edge for inserting a cut into the insulation prior to the insulation being stripped by a stripping element.